package router

import (
	"time"

	"github.com/go-gost/core/ingress"
	mdata "github.com/go-gost/core/metadata"
	"github.com/go-gost/core/router"
	"github.com/go-gost/core/sd"
	mdutil "github.com/go-gost/x/metadata/util"
	"github.com/go-gost/x/registry"
)

const (
	defaultTTL             = 15 * time.Second
	defaultBufferSize      = 4096
	defaultCacheExpiration = time.Second
)

type metadata struct {
	// readTimeout is the deadline for reading the initial relay protocol
	// handshake from the client connection. The deadline is cleared
	// after the handshake, so it does not affect subsequent data
	// transfer.
	// 0 or negative means no timeout is applied.
	readTimeout time.Duration
	bufferSize  int

	entryPoint        string
	ingress           ingress.Ingress
	sd                sd.SD
	sdCacheExpiration time.Duration
	sdRenewInterval   time.Duration

	router                router.Router
	routerCacheEnabled    bool
	routerCacheExpiration time.Duration

	observerPeriod       time.Duration
	observerResetTraffic bool

	limiterRefreshInterval time.Duration
	limiterCleanupInterval time.Duration
}

func (h *routerHandler) parseMetadata(md mdata.Metadata) (err error) {
	h.md.readTimeout = mdutil.GetDuration(md, "readTimeout")
	h.md.bufferSize = mdutil.GetInt(md, "router.bufferSize", "bufferSize")
	if h.md.bufferSize <= 0 {
		h.md.bufferSize = defaultBufferSize
	}

	h.md.entryPoint = mdutil.GetString(md, "entrypoint")
	h.md.ingress = registry.IngressRegistry().Get(mdutil.GetString(md, "ingress"))

	h.md.sd = registry.SDRegistry().Get(mdutil.GetString(md, "sd"))
	h.md.sdCacheExpiration = mdutil.GetDuration(md, "sd.cache.expiration")
	if h.md.sdCacheExpiration <= 0 {
		h.md.sdCacheExpiration = defaultCacheExpiration
	}
	h.md.sdRenewInterval = mdutil.GetDuration(md, "sd.renewInterval")
	if h.md.sdRenewInterval < time.Second {
		h.md.sdRenewInterval = defaultTTL
	}

	h.md.router = registry.RouterRegistry().Get(mdutil.GetString(md, "router"))
	h.md.routerCacheEnabled = mdutil.GetBool(md, "router.cache")
	h.md.routerCacheExpiration = mdutil.GetDuration(md, "router.cache.expiration")
	if h.md.routerCacheExpiration <= 0 {
		h.md.routerCacheExpiration = defaultCacheExpiration
	}

	h.md.observerPeriod = mdutil.GetDuration(md, "observePeriod", "observer.period", "observer.observePeriod")
	if h.md.observerPeriod == 0 {
		h.md.observerPeriod = 5 * time.Second
	}
	if h.md.observerPeriod < time.Second {
		h.md.observerPeriod = time.Second
	}
	h.md.observerResetTraffic = mdutil.GetBool(md, "observer.resetTraffic")

	h.md.limiterRefreshInterval = mdutil.GetDuration(md, "limiter.refreshInterval")
	h.md.limiterCleanupInterval = mdutil.GetDuration(md, "limiter.cleanupInterval")

	return
}